1 // SPDX-License-Identifier: GPL-2.0-only
3 * (C) 1997 Linus Torvalds
4 * (C) 1999 Andrea Arcangeli <andrea@suse.de> (dynamic inode allocation)
6 #include <linux/export.h>
9 #include <linux/backing-dev.h>
10 #include <linux/hash.h>
11 #include <linux/swap.h>
12 #include <linux/security.h>
13 #include <linux/cdev.h>
14 #include <linux/memblock.h>
15 #include <linux/fsnotify.h>
16 #include <linux/mount.h>
17 #include <linux/posix_acl.h>
18 #include <linux/prefetch.h>
19 #include <linux/buffer_head.h> /* for inode_has_buffers */
20 #include <linux/ratelimit.h>
21 #include <linux/list_lru.h>
22 #include <linux/iversion.h>
23 #include <trace/events/writeback.h>
27 * Inode locking rules:
29 * inode->i_lock protects:
30 * inode->i_state, inode->i_hash, __iget()
31 * Inode LRU list locks protect:
32 * inode->i_sb->s_inode_lru, inode->i_lru
33 * inode->i_sb->s_inode_list_lock protects:
34 * inode->i_sb->s_inodes, inode->i_sb_list
35 * bdi->wb.list_lock protects:
36 * bdi->wb.b_{dirty,io,more_io,dirty_time}, inode->i_io_list
37 * inode_hash_lock protects:
38 * inode_hashtable, inode->i_hash
42 * inode->i_sb->s_inode_list_lock
44 * Inode LRU list locks
50 * inode->i_sb->s_inode_list_lock
57 static unsigned int i_hash_mask __read_mostly
;
58 static unsigned int i_hash_shift __read_mostly
;
59 static struct hlist_head
*inode_hashtable __read_mostly
;
60 static __cacheline_aligned_in_smp
DEFINE_SPINLOCK(inode_hash_lock
);
63 * Empty aops. Can be used for the cases where the user does not
64 * define any of the address_space operations.
66 const struct address_space_operations empty_aops
= {
68 EXPORT_SYMBOL(empty_aops
);
71 * Statistics gathering..
73 struct inodes_stat_t inodes_stat
;
75 static DEFINE_PER_CPU(unsigned long, nr_inodes
);
76 static DEFINE_PER_CPU(unsigned long, nr_unused
);
78 static struct kmem_cache
*inode_cachep __read_mostly
;
80 static long get_nr_inodes(void)
84 for_each_possible_cpu(i
)
85 sum
+= per_cpu(nr_inodes
, i
);
86 return sum
< 0 ? 0 : sum
;
89 static inline long get_nr_inodes_unused(void)
93 for_each_possible_cpu(i
)
94 sum
+= per_cpu(nr_unused
, i
);
95 return sum
< 0 ? 0 : sum
;
98 long get_nr_dirty_inodes(void)
100 /* not actually dirty inodes, but a wild approximation */
101 long nr_dirty
= get_nr_inodes() - get_nr_inodes_unused();
102 return nr_dirty
> 0 ? nr_dirty
: 0;
106 * Handle nr_inode sysctl
109 int proc_nr_inodes(struct ctl_table
*table
, int write
,
110 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
112 inodes_stat
.nr_inodes
= get_nr_inodes();
113 inodes_stat
.nr_unused
= get_nr_inodes_unused();
114 return proc_doulongvec_minmax(table
, write
, buffer
, lenp
, ppos
);
118 static int no_open(struct inode
*inode
, struct file
*file
)
124 * inode_init_always - perform inode structure initialisation
125 * @sb: superblock inode belongs to
126 * @inode: inode to initialise
128 * These are initializations that need to be done on every inode
129 * allocation as the fields are not initialised by slab allocation.
131 int inode_init_always(struct super_block
*sb
, struct inode
*inode
)
133 static const struct inode_operations empty_iops
;
134 static const struct file_operations no_open_fops
= {.open
= no_open
};
135 struct address_space
*const mapping
= &inode
->i_data
;
138 inode
->i_blkbits
= sb
->s_blocksize_bits
;
140 atomic_set(&inode
->i_count
, 1);
141 inode
->i_op
= &empty_iops
;
142 inode
->i_fop
= &no_open_fops
;
143 inode
->__i_nlink
= 1;
144 inode
->i_opflags
= 0;
146 inode
->i_opflags
|= IOP_XATTR
;
147 i_uid_write(inode
, 0);
148 i_gid_write(inode
, 0);
149 atomic_set(&inode
->i_writecount
, 0);
151 inode
->i_write_hint
= WRITE_LIFE_NOT_SET
;
154 inode
->i_generation
= 0;
155 inode
->i_pipe
= NULL
;
156 inode
->i_bdev
= NULL
;
157 inode
->i_cdev
= NULL
;
158 inode
->i_link
= NULL
;
159 inode
->i_dir_seq
= 0;
161 inode
->dirtied_when
= 0;
163 #ifdef CONFIG_CGROUP_WRITEBACK
164 inode
->i_wb_frn_winner
= 0;
165 inode
->i_wb_frn_avg_time
= 0;
166 inode
->i_wb_frn_history
= 0;
169 if (security_inode_alloc(inode
))
171 spin_lock_init(&inode
->i_lock
);
172 lockdep_set_class(&inode
->i_lock
, &sb
->s_type
->i_lock_key
);
174 init_rwsem(&inode
->i_rwsem
);
175 lockdep_set_class(&inode
->i_rwsem
, &sb
->s_type
->i_mutex_key
);
177 atomic_set(&inode
->i_dio_count
, 0);
179 mapping
->a_ops
= &empty_aops
;
180 mapping
->host
= inode
;
183 atomic_set(&mapping
->i_mmap_writable
, 0);
184 #ifdef CONFIG_READ_ONLY_THP_FOR_FS
185 atomic_set(&mapping
->nr_thps
, 0);
187 mapping_set_gfp_mask(mapping
, GFP_HIGHUSER_MOVABLE
);
188 mapping
->private_data
= NULL
;
189 mapping
->writeback_index
= 0;
190 inode
->i_private
= NULL
;
191 inode
->i_mapping
= mapping
;
192 INIT_HLIST_HEAD(&inode
->i_dentry
); /* buggered by rcu freeing */
193 #ifdef CONFIG_FS_POSIX_ACL
194 inode
->i_acl
= inode
->i_default_acl
= ACL_NOT_CACHED
;
197 #ifdef CONFIG_FSNOTIFY
198 inode
->i_fsnotify_mask
= 0;
200 inode
->i_flctx
= NULL
;
201 this_cpu_inc(nr_inodes
);
207 EXPORT_SYMBOL(inode_init_always
);
209 void free_inode_nonrcu(struct inode
*inode
)
211 kmem_cache_free(inode_cachep
, inode
);
213 EXPORT_SYMBOL(free_inode_nonrcu
);
215 static void i_callback(struct rcu_head
*head
)
217 struct inode
*inode
= container_of(head
, struct inode
, i_rcu
);
218 if (inode
->free_inode
)
219 inode
->free_inode(inode
);
221 free_inode_nonrcu(inode
);
224 static struct inode
*alloc_inode(struct super_block
*sb
)
226 const struct super_operations
*ops
= sb
->s_op
;
229 if (ops
->alloc_inode
)
230 inode
= ops
->alloc_inode(sb
);
232 inode
= kmem_cache_alloc(inode_cachep
, GFP_KERNEL
);
237 if (unlikely(inode_init_always(sb
, inode
))) {
238 if (ops
->destroy_inode
) {
239 ops
->destroy_inode(inode
);
240 if (!ops
->free_inode
)
243 inode
->free_inode
= ops
->free_inode
;
244 i_callback(&inode
->i_rcu
);
251 void __destroy_inode(struct inode
*inode
)
253 BUG_ON(inode_has_buffers(inode
));
254 inode_detach_wb(inode
);
255 security_inode_free(inode
);
256 fsnotify_inode_delete(inode
);
257 locks_free_lock_context(inode
);
258 if (!inode
->i_nlink
) {
259 WARN_ON(atomic_long_read(&inode
->i_sb
->s_remove_count
) == 0);
260 atomic_long_dec(&inode
->i_sb
->s_remove_count
);
263 #ifdef CONFIG_FS_POSIX_ACL
264 if (inode
->i_acl
&& !is_uncached_acl(inode
->i_acl
))
265 posix_acl_release(inode
->i_acl
);
266 if (inode
->i_default_acl
&& !is_uncached_acl(inode
->i_default_acl
))
267 posix_acl_release(inode
->i_default_acl
);
269 this_cpu_dec(nr_inodes
);
271 EXPORT_SYMBOL(__destroy_inode
);
273 static void destroy_inode(struct inode
*inode
)
275 const struct super_operations
*ops
= inode
->i_sb
->s_op
;
277 BUG_ON(!list_empty(&inode
->i_lru
));
278 __destroy_inode(inode
);
279 if (ops
->destroy_inode
) {
280 ops
->destroy_inode(inode
);
281 if (!ops
->free_inode
)
284 inode
->free_inode
= ops
->free_inode
;
285 call_rcu(&inode
->i_rcu
, i_callback
);
289 * drop_nlink - directly drop an inode's link count
292 * This is a low-level filesystem helper to replace any
293 * direct filesystem manipulation of i_nlink. In cases
294 * where we are attempting to track writes to the
295 * filesystem, a decrement to zero means an imminent
296 * write when the file is truncated and actually unlinked
299 void drop_nlink(struct inode
*inode
)
301 WARN_ON(inode
->i_nlink
== 0);
304 atomic_long_inc(&inode
->i_sb
->s_remove_count
);
306 EXPORT_SYMBOL(drop_nlink
);
309 * clear_nlink - directly zero an inode's link count
312 * This is a low-level filesystem helper to replace any
313 * direct filesystem manipulation of i_nlink. See
314 * drop_nlink() for why we care about i_nlink hitting zero.
316 void clear_nlink(struct inode
*inode
)
318 if (inode
->i_nlink
) {
319 inode
->__i_nlink
= 0;
320 atomic_long_inc(&inode
->i_sb
->s_remove_count
);
323 EXPORT_SYMBOL(clear_nlink
);
326 * set_nlink - directly set an inode's link count
328 * @nlink: new nlink (should be non-zero)
330 * This is a low-level filesystem helper to replace any
331 * direct filesystem manipulation of i_nlink.
333 void set_nlink(struct inode
*inode
, unsigned int nlink
)
338 /* Yes, some filesystems do change nlink from zero to one */
339 if (inode
->i_nlink
== 0)
340 atomic_long_dec(&inode
->i_sb
->s_remove_count
);
342 inode
->__i_nlink
= nlink
;
345 EXPORT_SYMBOL(set_nlink
);
348 * inc_nlink - directly increment an inode's link count
351 * This is a low-level filesystem helper to replace any
352 * direct filesystem manipulation of i_nlink. Currently,
353 * it is only here for parity with dec_nlink().
355 void inc_nlink(struct inode
*inode
)
357 if (unlikely(inode
->i_nlink
== 0)) {
358 WARN_ON(!(inode
->i_state
& I_LINKABLE
));
359 atomic_long_dec(&inode
->i_sb
->s_remove_count
);
364 EXPORT_SYMBOL(inc_nlink
);
366 static void __address_space_init_once(struct address_space
*mapping
)
368 xa_init_flags(&mapping
->i_pages
, XA_FLAGS_LOCK_IRQ
| XA_FLAGS_ACCOUNT
);
369 init_rwsem(&mapping
->i_mmap_rwsem
);
370 INIT_LIST_HEAD(&mapping
->private_list
);
371 spin_lock_init(&mapping
->private_lock
);
372 mapping
->i_mmap
= RB_ROOT_CACHED
;
375 void address_space_init_once(struct address_space
*mapping
)
377 memset(mapping
, 0, sizeof(*mapping
));
378 __address_space_init_once(mapping
);
380 EXPORT_SYMBOL(address_space_init_once
);
383 * These are initializations that only need to be done
384 * once, because the fields are idempotent across use
385 * of the inode, so let the slab aware of that.
387 void inode_init_once(struct inode
*inode
)
389 memset(inode
, 0, sizeof(*inode
));
390 INIT_HLIST_NODE(&inode
->i_hash
);
391 INIT_LIST_HEAD(&inode
->i_devices
);
392 INIT_LIST_HEAD(&inode
->i_io_list
);
393 INIT_LIST_HEAD(&inode
->i_wb_list
);
394 INIT_LIST_HEAD(&inode
->i_lru
);
395 __address_space_init_once(&inode
->i_data
);
396 i_size_ordered_init(inode
);
398 EXPORT_SYMBOL(inode_init_once
);
400 static void init_once(void *foo
)
402 struct inode
*inode
= (struct inode
*) foo
;
404 inode_init_once(inode
);
408 * inode->i_lock must be held
410 void __iget(struct inode
*inode
)
412 atomic_inc(&inode
->i_count
);
416 * get additional reference to inode; caller must already hold one.
418 void ihold(struct inode
*inode
)
420 WARN_ON(atomic_inc_return(&inode
->i_count
) < 2);
422 EXPORT_SYMBOL(ihold
);
424 static void inode_lru_list_add(struct inode
*inode
)
426 if (list_lru_add(&inode
->i_sb
->s_inode_lru
, &inode
->i_lru
))
427 this_cpu_inc(nr_unused
);
429 inode
->i_state
|= I_REFERENCED
;
433 * Add inode to LRU if needed (inode is unused and clean).
435 * Needs inode->i_lock held.
437 void inode_add_lru(struct inode
*inode
)
439 if (!(inode
->i_state
& (I_DIRTY_ALL
| I_SYNC
|
440 I_FREEING
| I_WILL_FREE
)) &&
441 !atomic_read(&inode
->i_count
) && inode
->i_sb
->s_flags
& SB_ACTIVE
)
442 inode_lru_list_add(inode
);
446 static void inode_lru_list_del(struct inode
*inode
)
449 if (list_lru_del(&inode
->i_sb
->s_inode_lru
, &inode
->i_lru
))
450 this_cpu_dec(nr_unused
);
454 * inode_sb_list_add - add inode to the superblock list of inodes
455 * @inode: inode to add
457 void inode_sb_list_add(struct inode
*inode
)
459 spin_lock(&inode
->i_sb
->s_inode_list_lock
);
460 list_add(&inode
->i_sb_list
, &inode
->i_sb
->s_inodes
);
461 spin_unlock(&inode
->i_sb
->s_inode_list_lock
);
463 EXPORT_SYMBOL_GPL(inode_sb_list_add
);
465 static inline void inode_sb_list_del(struct inode
*inode
)
467 if (!list_empty(&inode
->i_sb_list
)) {
468 spin_lock(&inode
->i_sb
->s_inode_list_lock
);
469 list_del_init(&inode
->i_sb_list
);
470 spin_unlock(&inode
->i_sb
->s_inode_list_lock
);
474 static unsigned long hash(struct super_block
*sb
, unsigned long hashval
)
478 tmp
= (hashval
* (unsigned long)sb
) ^ (GOLDEN_RATIO_PRIME
+ hashval
) /
480 tmp
= tmp
^ ((tmp
^ GOLDEN_RATIO_PRIME
) >> i_hash_shift
);
481 return tmp
& i_hash_mask
;
485 * __insert_inode_hash - hash an inode
486 * @inode: unhashed inode
487 * @hashval: unsigned long value used to locate this object in the
490 * Add an inode to the inode hash for this superblock.
492 void __insert_inode_hash(struct inode
*inode
, unsigned long hashval
)
494 struct hlist_head
*b
= inode_hashtable
+ hash(inode
->i_sb
, hashval
);
496 spin_lock(&inode_hash_lock
);
497 spin_lock(&inode
->i_lock
);
498 hlist_add_head(&inode
->i_hash
, b
);
499 spin_unlock(&inode
->i_lock
);
500 spin_unlock(&inode_hash_lock
);
502 EXPORT_SYMBOL(__insert_inode_hash
);
505 * __remove_inode_hash - remove an inode from the hash
506 * @inode: inode to unhash
508 * Remove an inode from the superblock.
510 void __remove_inode_hash(struct inode
*inode
)
512 spin_lock(&inode_hash_lock
);
513 spin_lock(&inode
->i_lock
);
514 hlist_del_init(&inode
->i_hash
);
515 spin_unlock(&inode
->i_lock
);
516 spin_unlock(&inode_hash_lock
);
518 EXPORT_SYMBOL(__remove_inode_hash
);
520 void clear_inode(struct inode
*inode
)
523 * We have to cycle the i_pages lock here because reclaim can be in the
524 * process of removing the last page (in __delete_from_page_cache())
525 * and we must not free the mapping under it.
527 xa_lock_irq(&inode
->i_data
.i_pages
);
528 BUG_ON(inode
->i_data
.nrpages
);
529 BUG_ON(inode
->i_data
.nrexceptional
);
530 xa_unlock_irq(&inode
->i_data
.i_pages
);
531 BUG_ON(!list_empty(&inode
->i_data
.private_list
));
532 BUG_ON(!(inode
->i_state
& I_FREEING
));
533 BUG_ON(inode
->i_state
& I_CLEAR
);
534 BUG_ON(!list_empty(&inode
->i_wb_list
));
535 /* don't need i_lock here, no concurrent mods to i_state */
536 inode
->i_state
= I_FREEING
| I_CLEAR
;
538 EXPORT_SYMBOL(clear_inode
);
541 * Free the inode passed in, removing it from the lists it is still connected
542 * to. We remove any pages still attached to the inode and wait for any IO that
543 * is still in progress before finally destroying the inode.
545 * An inode must already be marked I_FREEING so that we avoid the inode being
546 * moved back onto lists if we race with other code that manipulates the lists
547 * (e.g. writeback_single_inode). The caller is responsible for setting this.
549 * An inode must already be removed from the LRU list before being evicted from
550 * the cache. This should occur atomically with setting the I_FREEING state
551 * flag, so no inodes here should ever be on the LRU when being evicted.
553 static void evict(struct inode
*inode
)
555 const struct super_operations
*op
= inode
->i_sb
->s_op
;
557 BUG_ON(!(inode
->i_state
& I_FREEING
));
558 BUG_ON(!list_empty(&inode
->i_lru
));
560 if (!list_empty(&inode
->i_io_list
))
561 inode_io_list_del(inode
);
563 inode_sb_list_del(inode
);
566 * Wait for flusher thread to be done with the inode so that filesystem
567 * does not start destroying it while writeback is still running. Since
568 * the inode has I_FREEING set, flusher thread won't start new work on
569 * the inode. We just have to wait for running writeback to finish.
571 inode_wait_for_writeback(inode
);
573 if (op
->evict_inode
) {
574 op
->evict_inode(inode
);
576 truncate_inode_pages_final(&inode
->i_data
);
579 if (S_ISBLK(inode
->i_mode
) && inode
->i_bdev
)
581 if (S_ISCHR(inode
->i_mode
) && inode
->i_cdev
)
584 remove_inode_hash(inode
);
586 spin_lock(&inode
->i_lock
);
587 wake_up_bit(&inode
->i_state
, __I_NEW
);
588 BUG_ON(inode
->i_state
!= (I_FREEING
| I_CLEAR
));
589 spin_unlock(&inode
->i_lock
);
591 destroy_inode(inode
);
595 * dispose_list - dispose of the contents of a local list
596 * @head: the head of the list to free
598 * Dispose-list gets a local list with local inodes in it, so it doesn't
599 * need to worry about list corruption and SMP locks.
601 static void dispose_list(struct list_head
*head
)
603 while (!list_empty(head
)) {
606 inode
= list_first_entry(head
, struct inode
, i_lru
);
607 list_del_init(&inode
->i_lru
);
615 * evict_inodes - evict all evictable inodes for a superblock
616 * @sb: superblock to operate on
618 * Make sure that no inodes with zero refcount are retained. This is
619 * called by superblock shutdown after having SB_ACTIVE flag removed,
620 * so any inode reaching zero refcount during or after that call will
621 * be immediately evicted.
623 void evict_inodes(struct super_block
*sb
)
625 struct inode
*inode
, *next
;
629 spin_lock(&sb
->s_inode_list_lock
);
630 list_for_each_entry_safe(inode
, next
, &sb
->s_inodes
, i_sb_list
) {
631 if (atomic_read(&inode
->i_count
))
634 spin_lock(&inode
->i_lock
);
635 if (inode
->i_state
& (I_NEW
| I_FREEING
| I_WILL_FREE
)) {
636 spin_unlock(&inode
->i_lock
);
640 inode
->i_state
|= I_FREEING
;
641 inode_lru_list_del(inode
);
642 spin_unlock(&inode
->i_lock
);
643 list_add(&inode
->i_lru
, &dispose
);
646 * We can have a ton of inodes to evict at unmount time given
647 * enough memory, check to see if we need to go to sleep for a
648 * bit so we don't livelock.
650 if (need_resched()) {
651 spin_unlock(&sb
->s_inode_list_lock
);
653 dispose_list(&dispose
);
657 spin_unlock(&sb
->s_inode_list_lock
);
659 dispose_list(&dispose
);
661 EXPORT_SYMBOL_GPL(evict_inodes
);
664 * invalidate_inodes - attempt to free all inodes on a superblock
665 * @sb: superblock to operate on
666 * @kill_dirty: flag to guide handling of dirty inodes
668 * Attempts to free all inodes for a given superblock. If there were any
669 * busy inodes return a non-zero value, else zero.
670 * If @kill_dirty is set, discard dirty inodes too, otherwise treat
673 int invalidate_inodes(struct super_block
*sb
, bool kill_dirty
)
676 struct inode
*inode
, *next
;
680 spin_lock(&sb
->s_inode_list_lock
);
681 list_for_each_entry_safe(inode
, next
, &sb
->s_inodes
, i_sb_list
) {
682 spin_lock(&inode
->i_lock
);
683 if (inode
->i_state
& (I_NEW
| I_FREEING
| I_WILL_FREE
)) {
684 spin_unlock(&inode
->i_lock
);
687 if (inode
->i_state
& I_DIRTY_ALL
&& !kill_dirty
) {
688 spin_unlock(&inode
->i_lock
);
692 if (atomic_read(&inode
->i_count
)) {
693 spin_unlock(&inode
->i_lock
);
698 inode
->i_state
|= I_FREEING
;
699 inode_lru_list_del(inode
);
700 spin_unlock(&inode
->i_lock
);
701 list_add(&inode
->i_lru
, &dispose
);
702 if (need_resched()) {
703 spin_unlock(&sb
->s_inode_list_lock
);
705 dispose_list(&dispose
);
709 spin_unlock(&sb
->s_inode_list_lock
);
711 dispose_list(&dispose
);
717 * Isolate the inode from the LRU in preparation for freeing it.
719 * Any inodes which are pinned purely because of attached pagecache have their
720 * pagecache removed. If the inode has metadata buffers attached to
721 * mapping->private_list then try to remove them.
723 * If the inode has the I_REFERENCED flag set, then it means that it has been
724 * used recently - the flag is set in iput_final(). When we encounter such an
725 * inode, clear the flag and move it to the back of the LRU so it gets another
726 * pass through the LRU before it gets reclaimed. This is necessary because of
727 * the fact we are doing lazy LRU updates to minimise lock contention so the
728 * LRU does not have strict ordering. Hence we don't want to reclaim inodes
729 * with this flag set because they are the inodes that are out of order.
731 static enum lru_status
inode_lru_isolate(struct list_head
*item
,
732 struct list_lru_one
*lru
, spinlock_t
*lru_lock
, void *arg
)
734 struct list_head
*freeable
= arg
;
735 struct inode
*inode
= container_of(item
, struct inode
, i_lru
);
738 * we are inverting the lru lock/inode->i_lock here, so use a trylock.
739 * If we fail to get the lock, just skip it.
741 if (!spin_trylock(&inode
->i_lock
))
745 * Referenced or dirty inodes are still in use. Give them another pass
746 * through the LRU as we canot reclaim them now.
748 if (atomic_read(&inode
->i_count
) ||
749 (inode
->i_state
& ~I_REFERENCED
)) {
750 list_lru_isolate(lru
, &inode
->i_lru
);
751 spin_unlock(&inode
->i_lock
);
752 this_cpu_dec(nr_unused
);
756 /* recently referenced inodes get one more pass */
757 if (inode
->i_state
& I_REFERENCED
) {
758 inode
->i_state
&= ~I_REFERENCED
;
759 spin_unlock(&inode
->i_lock
);
763 if (inode_has_buffers(inode
) || inode
->i_data
.nrpages
) {
765 spin_unlock(&inode
->i_lock
);
766 spin_unlock(lru_lock
);
767 if (remove_inode_buffers(inode
)) {
769 reap
= invalidate_mapping_pages(&inode
->i_data
, 0, -1);
770 if (current_is_kswapd())
771 __count_vm_events(KSWAPD_INODESTEAL
, reap
);
773 __count_vm_events(PGINODESTEAL
, reap
);
774 if (current
->reclaim_state
)
775 current
->reclaim_state
->reclaimed_slab
+= reap
;
782 WARN_ON(inode
->i_state
& I_NEW
);
783 inode
->i_state
|= I_FREEING
;
784 list_lru_isolate_move(lru
, &inode
->i_lru
, freeable
);
785 spin_unlock(&inode
->i_lock
);
787 this_cpu_dec(nr_unused
);
792 * Walk the superblock inode LRU for freeable inodes and attempt to free them.
793 * This is called from the superblock shrinker function with a number of inodes
794 * to trim from the LRU. Inodes to be freed are moved to a temporary list and
795 * then are freed outside inode_lock by dispose_list().
797 long prune_icache_sb(struct super_block
*sb
, struct shrink_control
*sc
)
802 freed
= list_lru_shrink_walk(&sb
->s_inode_lru
, sc
,
803 inode_lru_isolate
, &freeable
);
804 dispose_list(&freeable
);
808 static void __wait_on_freeing_inode(struct inode
*inode
);
810 * Called with the inode lock held.
812 static struct inode
*find_inode(struct super_block
*sb
,
813 struct hlist_head
*head
,
814 int (*test
)(struct inode
*, void *),
817 struct inode
*inode
= NULL
;
820 hlist_for_each_entry(inode
, head
, i_hash
) {
821 if (inode
->i_sb
!= sb
)
823 if (!test(inode
, data
))
825 spin_lock(&inode
->i_lock
);
826 if (inode
->i_state
& (I_FREEING
|I_WILL_FREE
)) {
827 __wait_on_freeing_inode(inode
);
830 if (unlikely(inode
->i_state
& I_CREATING
)) {
831 spin_unlock(&inode
->i_lock
);
832 return ERR_PTR(-ESTALE
);
835 spin_unlock(&inode
->i_lock
);
842 * find_inode_fast is the fast path version of find_inode, see the comment at
843 * iget_locked for details.
845 static struct inode
*find_inode_fast(struct super_block
*sb
,
846 struct hlist_head
*head
, unsigned long ino
)
848 struct inode
*inode
= NULL
;
851 hlist_for_each_entry(inode
, head
, i_hash
) {
852 if (inode
->i_ino
!= ino
)
854 if (inode
->i_sb
!= sb
)
856 spin_lock(&inode
->i_lock
);
857 if (inode
->i_state
& (I_FREEING
|I_WILL_FREE
)) {
858 __wait_on_freeing_inode(inode
);
861 if (unlikely(inode
->i_state
& I_CREATING
)) {
862 spin_unlock(&inode
->i_lock
);
863 return ERR_PTR(-ESTALE
);
866 spin_unlock(&inode
->i_lock
);
873 * Each cpu owns a range of LAST_INO_BATCH numbers.
874 * 'shared_last_ino' is dirtied only once out of LAST_INO_BATCH allocations,
875 * to renew the exhausted range.
877 * This does not significantly increase overflow rate because every CPU can
878 * consume at most LAST_INO_BATCH-1 unused inode numbers. So there is
879 * NR_CPUS*(LAST_INO_BATCH-1) wastage. At 4096 and 1024, this is ~0.1% of the
880 * 2^32 range, and is a worst-case. Even a 50% wastage would only increase
881 * overflow rate by 2x, which does not seem too significant.
883 * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW
884 * error if st_ino won't fit in target struct field. Use 32bit counter
885 * here to attempt to avoid that.
887 #define LAST_INO_BATCH 1024
888 static DEFINE_PER_CPU(unsigned int, last_ino
);
890 unsigned int get_next_ino(void)
892 unsigned int *p
= &get_cpu_var(last_ino
);
893 unsigned int res
= *p
;
896 if (unlikely((res
& (LAST_INO_BATCH
-1)) == 0)) {
897 static atomic_t shared_last_ino
;
898 int next
= atomic_add_return(LAST_INO_BATCH
, &shared_last_ino
);
900 res
= next
- LAST_INO_BATCH
;
905 /* get_next_ino should not provide a 0 inode number */
909 put_cpu_var(last_ino
);
912 EXPORT_SYMBOL(get_next_ino
);
915 * new_inode_pseudo - obtain an inode
918 * Allocates a new inode for given superblock.
919 * Inode wont be chained in superblock s_inodes list
921 * - fs can't be unmount
922 * - quotas, fsnotify, writeback can't work
924 struct inode
*new_inode_pseudo(struct super_block
*sb
)
926 struct inode
*inode
= alloc_inode(sb
);
929 spin_lock(&inode
->i_lock
);
931 spin_unlock(&inode
->i_lock
);
932 INIT_LIST_HEAD(&inode
->i_sb_list
);
938 * new_inode - obtain an inode
941 * Allocates a new inode for given superblock. The default gfp_mask
942 * for allocations related to inode->i_mapping is GFP_HIGHUSER_MOVABLE.
943 * If HIGHMEM pages are unsuitable or it is known that pages allocated
944 * for the page cache are not reclaimable or migratable,
945 * mapping_set_gfp_mask() must be called with suitable flags on the
946 * newly created inode's mapping
949 struct inode
*new_inode(struct super_block
*sb
)
953 spin_lock_prefetch(&sb
->s_inode_list_lock
);
955 inode
= new_inode_pseudo(sb
);
957 inode_sb_list_add(inode
);
960 EXPORT_SYMBOL(new_inode
);
962 #ifdef CONFIG_DEBUG_LOCK_ALLOC
963 void lockdep_annotate_inode_mutex_key(struct inode
*inode
)
965 if (S_ISDIR(inode
->i_mode
)) {
966 struct file_system_type
*type
= inode
->i_sb
->s_type
;
968 /* Set new key only if filesystem hasn't already changed it */
969 if (lockdep_match_class(&inode
->i_rwsem
, &type
->i_mutex_key
)) {
971 * ensure nobody is actually holding i_mutex
973 // mutex_destroy(&inode->i_mutex);
974 init_rwsem(&inode
->i_rwsem
);
975 lockdep_set_class(&inode
->i_rwsem
,
976 &type
->i_mutex_dir_key
);
980 EXPORT_SYMBOL(lockdep_annotate_inode_mutex_key
);
984 * unlock_new_inode - clear the I_NEW state and wake up any waiters
985 * @inode: new inode to unlock
987 * Called when the inode is fully initialised to clear the new state of the
988 * inode and wake up anyone waiting for the inode to finish initialisation.
990 void unlock_new_inode(struct inode
*inode
)
992 lockdep_annotate_inode_mutex_key(inode
);
993 spin_lock(&inode
->i_lock
);
994 WARN_ON(!(inode
->i_state
& I_NEW
));
995 inode
->i_state
&= ~I_NEW
& ~I_CREATING
;
997 wake_up_bit(&inode
->i_state
, __I_NEW
);
998 spin_unlock(&inode
->i_lock
);
1000 EXPORT_SYMBOL(unlock_new_inode
);
1002 void discard_new_inode(struct inode
*inode
)
1004 lockdep_annotate_inode_mutex_key(inode
);
1005 spin_lock(&inode
->i_lock
);
1006 WARN_ON(!(inode
->i_state
& I_NEW
));
1007 inode
->i_state
&= ~I_NEW
;
1009 wake_up_bit(&inode
->i_state
, __I_NEW
);
1010 spin_unlock(&inode
->i_lock
);
1013 EXPORT_SYMBOL(discard_new_inode
);
1016 * lock_two_nondirectories - take two i_mutexes on non-directory objects
1018 * Lock any non-NULL argument that is not a directory.
1019 * Zero, one or two objects may be locked by this function.
1021 * @inode1: first inode to lock
1022 * @inode2: second inode to lock
1024 void lock_two_nondirectories(struct inode
*inode1
, struct inode
*inode2
)
1026 if (inode1
> inode2
)
1027 swap(inode1
, inode2
);
1029 if (inode1
&& !S_ISDIR(inode1
->i_mode
))
1031 if (inode2
&& !S_ISDIR(inode2
->i_mode
) && inode2
!= inode1
)
1032 inode_lock_nested(inode2
, I_MUTEX_NONDIR2
);
1034 EXPORT_SYMBOL(lock_two_nondirectories
);
1037 * unlock_two_nondirectories - release locks from lock_two_nondirectories()
1038 * @inode1: first inode to unlock
1039 * @inode2: second inode to unlock
1041 void unlock_two_nondirectories(struct inode
*inode1
, struct inode
*inode2
)
1043 if (inode1
&& !S_ISDIR(inode1
->i_mode
))
1044 inode_unlock(inode1
);
1045 if (inode2
&& !S_ISDIR(inode2
->i_mode
) && inode2
!= inode1
)
1046 inode_unlock(inode2
);
1048 EXPORT_SYMBOL(unlock_two_nondirectories
);
1051 * inode_insert5 - obtain an inode from a mounted file system
1052 * @inode: pre-allocated inode to use for insert to cache
1053 * @hashval: hash value (usually inode number) to get
1054 * @test: callback used for comparisons between inodes
1055 * @set: callback used to initialize a new struct inode
1056 * @data: opaque data pointer to pass to @test and @set
1058 * Search for the inode specified by @hashval and @data in the inode cache,
1059 * and if present it is return it with an increased reference count. This is
1060 * a variant of iget5_locked() for callers that don't want to fail on memory
1061 * allocation of inode.
1063 * If the inode is not in cache, insert the pre-allocated inode to cache and
1064 * return it locked, hashed, and with the I_NEW flag set. The file system gets
1065 * to fill it in before unlocking it via unlock_new_inode().
1067 * Note both @test and @set are called with the inode_hash_lock held, so can't
1070 struct inode
*inode_insert5(struct inode
*inode
, unsigned long hashval
,
1071 int (*test
)(struct inode
*, void *),
1072 int (*set
)(struct inode
*, void *), void *data
)
1074 struct hlist_head
*head
= inode_hashtable
+ hash(inode
->i_sb
, hashval
);
1076 bool creating
= inode
->i_state
& I_CREATING
;
1079 spin_lock(&inode_hash_lock
);
1080 old
= find_inode(inode
->i_sb
, head
, test
, data
);
1081 if (unlikely(old
)) {
1083 * Uhhuh, somebody else created the same inode under us.
1084 * Use the old inode instead of the preallocated one.
1086 spin_unlock(&inode_hash_lock
);
1090 if (unlikely(inode_unhashed(old
))) {
1097 if (set
&& unlikely(set(inode
, data
))) {
1103 * Return the locked inode with I_NEW set, the
1104 * caller is responsible for filling in the contents
1106 spin_lock(&inode
->i_lock
);
1107 inode
->i_state
|= I_NEW
;
1108 hlist_add_head(&inode
->i_hash
, head
);
1109 spin_unlock(&inode
->i_lock
);
1111 inode_sb_list_add(inode
);
1113 spin_unlock(&inode_hash_lock
);
1117 EXPORT_SYMBOL(inode_insert5
);
1120 * iget5_locked - obtain an inode from a mounted file system
1121 * @sb: super block of file system
1122 * @hashval: hash value (usually inode number) to get
1123 * @test: callback used for comparisons between inodes
1124 * @set: callback used to initialize a new struct inode
1125 * @data: opaque data pointer to pass to @test and @set
1127 * Search for the inode specified by @hashval and @data in the inode cache,
1128 * and if present it is return it with an increased reference count. This is
1129 * a generalized version of iget_locked() for file systems where the inode
1130 * number is not sufficient for unique identification of an inode.
1132 * If the inode is not in cache, allocate a new inode and return it locked,
1133 * hashed, and with the I_NEW flag set. The file system gets to fill it in
1134 * before unlocking it via unlock_new_inode().
1136 * Note both @test and @set are called with the inode_hash_lock held, so can't
1139 struct inode
*iget5_locked(struct super_block
*sb
, unsigned long hashval
,
1140 int (*test
)(struct inode
*, void *),
1141 int (*set
)(struct inode
*, void *), void *data
)
1143 struct inode
*inode
= ilookup5(sb
, hashval
, test
, data
);
1146 struct inode
*new = alloc_inode(sb
);
1150 inode
= inode_insert5(new, hashval
, test
, set
, data
);
1151 if (unlikely(inode
!= new))
1157 EXPORT_SYMBOL(iget5_locked
);
1160 * iget_locked - obtain an inode from a mounted file system
1161 * @sb: super block of file system
1162 * @ino: inode number to get
1164 * Search for the inode specified by @ino in the inode cache and if present
1165 * return it with an increased reference count. This is for file systems
1166 * where the inode number is sufficient for unique identification of an inode.
1168 * If the inode is not in cache, allocate a new inode and return it locked,
1169 * hashed, and with the I_NEW flag set. The file system gets to fill it in
1170 * before unlocking it via unlock_new_inode().
1172 struct inode
*iget_locked(struct super_block
*sb
, unsigned long ino
)
1174 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, ino
);
1175 struct inode
*inode
;
1177 spin_lock(&inode_hash_lock
);
1178 inode
= find_inode_fast(sb
, head
, ino
);
1179 spin_unlock(&inode_hash_lock
);
1183 wait_on_inode(inode
);
1184 if (unlikely(inode_unhashed(inode
))) {
1191 inode
= alloc_inode(sb
);
1195 spin_lock(&inode_hash_lock
);
1196 /* We released the lock, so.. */
1197 old
= find_inode_fast(sb
, head
, ino
);
1200 spin_lock(&inode
->i_lock
);
1201 inode
->i_state
= I_NEW
;
1202 hlist_add_head(&inode
->i_hash
, head
);
1203 spin_unlock(&inode
->i_lock
);
1204 inode_sb_list_add(inode
);
1205 spin_unlock(&inode_hash_lock
);
1207 /* Return the locked inode with I_NEW set, the
1208 * caller is responsible for filling in the contents
1214 * Uhhuh, somebody else created the same inode under
1215 * us. Use the old inode instead of the one we just
1218 spin_unlock(&inode_hash_lock
);
1219 destroy_inode(inode
);
1223 wait_on_inode(inode
);
1224 if (unlikely(inode_unhashed(inode
))) {
1231 EXPORT_SYMBOL(iget_locked
);
1234 * search the inode cache for a matching inode number.
1235 * If we find one, then the inode number we are trying to
1236 * allocate is not unique and so we should not use it.
1238 * Returns 1 if the inode number is unique, 0 if it is not.
1240 static int test_inode_iunique(struct super_block
*sb
, unsigned long ino
)
1242 struct hlist_head
*b
= inode_hashtable
+ hash(sb
, ino
);
1243 struct inode
*inode
;
1245 spin_lock(&inode_hash_lock
);
1246 hlist_for_each_entry(inode
, b
, i_hash
) {
1247 if (inode
->i_ino
== ino
&& inode
->i_sb
== sb
) {
1248 spin_unlock(&inode_hash_lock
);
1252 spin_unlock(&inode_hash_lock
);
1258 * iunique - get a unique inode number
1260 * @max_reserved: highest reserved inode number
1262 * Obtain an inode number that is unique on the system for a given
1263 * superblock. This is used by file systems that have no natural
1264 * permanent inode numbering system. An inode number is returned that
1265 * is higher than the reserved limit but unique.
1268 * With a large number of inodes live on the file system this function
1269 * currently becomes quite slow.
1271 ino_t
iunique(struct super_block
*sb
, ino_t max_reserved
)
1274 * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW
1275 * error if st_ino won't fit in target struct field. Use 32bit counter
1276 * here to attempt to avoid that.
1278 static DEFINE_SPINLOCK(iunique_lock
);
1279 static unsigned int counter
;
1282 spin_lock(&iunique_lock
);
1284 if (counter
<= max_reserved
)
1285 counter
= max_reserved
+ 1;
1287 } while (!test_inode_iunique(sb
, res
));
1288 spin_unlock(&iunique_lock
);
1292 EXPORT_SYMBOL(iunique
);
1294 struct inode
*igrab(struct inode
*inode
)
1296 spin_lock(&inode
->i_lock
);
1297 if (!(inode
->i_state
& (I_FREEING
|I_WILL_FREE
))) {
1299 spin_unlock(&inode
->i_lock
);
1301 spin_unlock(&inode
->i_lock
);
1303 * Handle the case where s_op->clear_inode is not been
1304 * called yet, and somebody is calling igrab
1305 * while the inode is getting freed.
1311 EXPORT_SYMBOL(igrab
);
1314 * ilookup5_nowait - search for an inode in the inode cache
1315 * @sb: super block of file system to search
1316 * @hashval: hash value (usually inode number) to search for
1317 * @test: callback used for comparisons between inodes
1318 * @data: opaque data pointer to pass to @test
1320 * Search for the inode specified by @hashval and @data in the inode cache.
1321 * If the inode is in the cache, the inode is returned with an incremented
1324 * Note: I_NEW is not waited upon so you have to be very careful what you do
1325 * with the returned inode. You probably should be using ilookup5() instead.
1327 * Note2: @test is called with the inode_hash_lock held, so can't sleep.
1329 struct inode
*ilookup5_nowait(struct super_block
*sb
, unsigned long hashval
,
1330 int (*test
)(struct inode
*, void *), void *data
)
1332 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, hashval
);
1333 struct inode
*inode
;
1335 spin_lock(&inode_hash_lock
);
1336 inode
= find_inode(sb
, head
, test
, data
);
1337 spin_unlock(&inode_hash_lock
);
1339 return IS_ERR(inode
) ? NULL
: inode
;
1341 EXPORT_SYMBOL(ilookup5_nowait
);
1344 * ilookup5 - search for an inode in the inode cache
1345 * @sb: super block of file system to search
1346 * @hashval: hash value (usually inode number) to search for
1347 * @test: callback used for comparisons between inodes
1348 * @data: opaque data pointer to pass to @test
1350 * Search for the inode specified by @hashval and @data in the inode cache,
1351 * and if the inode is in the cache, return the inode with an incremented
1352 * reference count. Waits on I_NEW before returning the inode.
1353 * returned with an incremented reference count.
1355 * This is a generalized version of ilookup() for file systems where the
1356 * inode number is not sufficient for unique identification of an inode.
1358 * Note: @test is called with the inode_hash_lock held, so can't sleep.
1360 struct inode
*ilookup5(struct super_block
*sb
, unsigned long hashval
,
1361 int (*test
)(struct inode
*, void *), void *data
)
1363 struct inode
*inode
;
1365 inode
= ilookup5_nowait(sb
, hashval
, test
, data
);
1367 wait_on_inode(inode
);
1368 if (unlikely(inode_unhashed(inode
))) {
1375 EXPORT_SYMBOL(ilookup5
);
1378 * ilookup - search for an inode in the inode cache
1379 * @sb: super block of file system to search
1380 * @ino: inode number to search for
1382 * Search for the inode @ino in the inode cache, and if the inode is in the
1383 * cache, the inode is returned with an incremented reference count.
1385 struct inode
*ilookup(struct super_block
*sb
, unsigned long ino
)
1387 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, ino
);
1388 struct inode
*inode
;
1390 spin_lock(&inode_hash_lock
);
1391 inode
= find_inode_fast(sb
, head
, ino
);
1392 spin_unlock(&inode_hash_lock
);
1397 wait_on_inode(inode
);
1398 if (unlikely(inode_unhashed(inode
))) {
1405 EXPORT_SYMBOL(ilookup
);
1408 * find_inode_nowait - find an inode in the inode cache
1409 * @sb: super block of file system to search
1410 * @hashval: hash value (usually inode number) to search for
1411 * @match: callback used for comparisons between inodes
1412 * @data: opaque data pointer to pass to @match
1414 * Search for the inode specified by @hashval and @data in the inode
1415 * cache, where the helper function @match will return 0 if the inode
1416 * does not match, 1 if the inode does match, and -1 if the search
1417 * should be stopped. The @match function must be responsible for
1418 * taking the i_lock spin_lock and checking i_state for an inode being
1419 * freed or being initialized, and incrementing the reference count
1420 * before returning 1. It also must not sleep, since it is called with
1421 * the inode_hash_lock spinlock held.
1423 * This is a even more generalized version of ilookup5() when the
1424 * function must never block --- find_inode() can block in
1425 * __wait_on_freeing_inode() --- or when the caller can not increment
1426 * the reference count because the resulting iput() might cause an
1427 * inode eviction. The tradeoff is that the @match funtion must be
1428 * very carefully implemented.
1430 struct inode
*find_inode_nowait(struct super_block
*sb
,
1431 unsigned long hashval
,
1432 int (*match
)(struct inode
*, unsigned long,
1436 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, hashval
);
1437 struct inode
*inode
, *ret_inode
= NULL
;
1440 spin_lock(&inode_hash_lock
);
1441 hlist_for_each_entry(inode
, head
, i_hash
) {
1442 if (inode
->i_sb
!= sb
)
1444 mval
= match(inode
, hashval
, data
);
1452 spin_unlock(&inode_hash_lock
);
1455 EXPORT_SYMBOL(find_inode_nowait
);
1457 int insert_inode_locked(struct inode
*inode
)
1459 struct super_block
*sb
= inode
->i_sb
;
1460 ino_t ino
= inode
->i_ino
;
1461 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, ino
);
1464 struct inode
*old
= NULL
;
1465 spin_lock(&inode_hash_lock
);
1466 hlist_for_each_entry(old
, head
, i_hash
) {
1467 if (old
->i_ino
!= ino
)
1469 if (old
->i_sb
!= sb
)
1471 spin_lock(&old
->i_lock
);
1472 if (old
->i_state
& (I_FREEING
|I_WILL_FREE
)) {
1473 spin_unlock(&old
->i_lock
);
1479 spin_lock(&inode
->i_lock
);
1480 inode
->i_state
|= I_NEW
| I_CREATING
;
1481 hlist_add_head(&inode
->i_hash
, head
);
1482 spin_unlock(&inode
->i_lock
);
1483 spin_unlock(&inode_hash_lock
);
1486 if (unlikely(old
->i_state
& I_CREATING
)) {
1487 spin_unlock(&old
->i_lock
);
1488 spin_unlock(&inode_hash_lock
);
1492 spin_unlock(&old
->i_lock
);
1493 spin_unlock(&inode_hash_lock
);
1495 if (unlikely(!inode_unhashed(old
))) {
1502 EXPORT_SYMBOL(insert_inode_locked
);
1504 int insert_inode_locked4(struct inode
*inode
, unsigned long hashval
,
1505 int (*test
)(struct inode
*, void *), void *data
)
1509 inode
->i_state
|= I_CREATING
;
1510 old
= inode_insert5(inode
, hashval
, test
, NULL
, data
);
1518 EXPORT_SYMBOL(insert_inode_locked4
);
1521 int generic_delete_inode(struct inode
*inode
)
1525 EXPORT_SYMBOL(generic_delete_inode
);
1528 * Called when we're dropping the last reference
1531 * Call the FS "drop_inode()" function, defaulting to
1532 * the legacy UNIX filesystem behaviour. If it tells
1533 * us to evict inode, do so. Otherwise, retain inode
1534 * in cache if fs is alive, sync and evict if fs is
1537 static void iput_final(struct inode
*inode
)
1539 struct super_block
*sb
= inode
->i_sb
;
1540 const struct super_operations
*op
= inode
->i_sb
->s_op
;
1543 WARN_ON(inode
->i_state
& I_NEW
);
1546 drop
= op
->drop_inode(inode
);
1548 drop
= generic_drop_inode(inode
);
1550 if (!drop
&& (sb
->s_flags
& SB_ACTIVE
)) {
1551 inode_add_lru(inode
);
1552 spin_unlock(&inode
->i_lock
);
1557 inode
->i_state
|= I_WILL_FREE
;
1558 spin_unlock(&inode
->i_lock
);
1559 write_inode_now(inode
, 1);
1560 spin_lock(&inode
->i_lock
);
1561 WARN_ON(inode
->i_state
& I_NEW
);
1562 inode
->i_state
&= ~I_WILL_FREE
;
1565 inode
->i_state
|= I_FREEING
;
1566 if (!list_empty(&inode
->i_lru
))
1567 inode_lru_list_del(inode
);
1568 spin_unlock(&inode
->i_lock
);
1574 * iput - put an inode
1575 * @inode: inode to put
1577 * Puts an inode, dropping its usage count. If the inode use count hits
1578 * zero, the inode is then freed and may also be destroyed.
1580 * Consequently, iput() can sleep.
1582 void iput(struct inode
*inode
)
1586 BUG_ON(inode
->i_state
& I_CLEAR
);
1588 if (atomic_dec_and_lock(&inode
->i_count
, &inode
->i_lock
)) {
1589 if (inode
->i_nlink
&& (inode
->i_state
& I_DIRTY_TIME
)) {
1590 atomic_inc(&inode
->i_count
);
1591 spin_unlock(&inode
->i_lock
);
1592 trace_writeback_lazytime_iput(inode
);
1593 mark_inode_dirty_sync(inode
);
1599 EXPORT_SYMBOL(iput
);
1602 * bmap - find a block number in a file
1603 * @inode: inode of file
1604 * @block: block to find
1606 * Returns the block number on the device holding the inode that
1607 * is the disk block number for the block of the file requested.
1608 * That is, asked for block 4 of inode 1 the function will return the
1609 * disk block relative to the disk start that holds that block of the
1612 sector_t
bmap(struct inode
*inode
, sector_t block
)
1615 if (inode
->i_mapping
->a_ops
->bmap
)
1616 res
= inode
->i_mapping
->a_ops
->bmap(inode
->i_mapping
, block
);
1619 EXPORT_SYMBOL(bmap
);
1622 * With relative atime, only update atime if the previous atime is
1623 * earlier than either the ctime or mtime or if at least a day has
1624 * passed since the last atime update.
1626 static int relatime_need_update(struct vfsmount
*mnt
, struct inode
*inode
,
1627 struct timespec64 now
)
1630 if (!(mnt
->mnt_flags
& MNT_RELATIME
))
1633 * Is mtime younger than atime? If yes, update atime:
1635 if (timespec64_compare(&inode
->i_mtime
, &inode
->i_atime
) >= 0)
1638 * Is ctime younger than atime? If yes, update atime:
1640 if (timespec64_compare(&inode
->i_ctime
, &inode
->i_atime
) >= 0)
1644 * Is the previous atime value older than a day? If yes,
1647 if ((long)(now
.tv_sec
- inode
->i_atime
.tv_sec
) >= 24*60*60)
1650 * Good, we can skip the atime update:
1655 int generic_update_time(struct inode
*inode
, struct timespec64
*time
, int flags
)
1657 int iflags
= I_DIRTY_TIME
;
1660 if (flags
& S_ATIME
)
1661 inode
->i_atime
= *time
;
1662 if (flags
& S_VERSION
)
1663 dirty
= inode_maybe_inc_iversion(inode
, false);
1664 if (flags
& S_CTIME
)
1665 inode
->i_ctime
= *time
;
1666 if (flags
& S_MTIME
)
1667 inode
->i_mtime
= *time
;
1668 if ((flags
& (S_ATIME
| S_CTIME
| S_MTIME
)) &&
1669 !(inode
->i_sb
->s_flags
& SB_LAZYTIME
))
1673 iflags
|= I_DIRTY_SYNC
;
1674 __mark_inode_dirty(inode
, iflags
);
1677 EXPORT_SYMBOL(generic_update_time
);
1680 * This does the actual work of updating an inodes time or version. Must have
1681 * had called mnt_want_write() before calling this.
1683 static int update_time(struct inode
*inode
, struct timespec64
*time
, int flags
)
1685 int (*update_time
)(struct inode
*, struct timespec64
*, int);
1687 update_time
= inode
->i_op
->update_time
? inode
->i_op
->update_time
:
1688 generic_update_time
;
1690 return update_time(inode
, time
, flags
);
1694 * touch_atime - update the access time
1695 * @path: the &struct path to update
1696 * @inode: inode to update
1698 * Update the accessed time on an inode and mark it for writeback.
1699 * This function automatically handles read only file systems and media,
1700 * as well as the "noatime" flag and inode specific "noatime" markers.
1702 bool atime_needs_update(const struct path
*path
, struct inode
*inode
)
1704 struct vfsmount
*mnt
= path
->mnt
;
1705 struct timespec64 now
;
1707 if (inode
->i_flags
& S_NOATIME
)
1710 /* Atime updates will likely cause i_uid and i_gid to be written
1711 * back improprely if their true value is unknown to the vfs.
1713 if (HAS_UNMAPPED_ID(inode
))
1716 if (IS_NOATIME(inode
))
1718 if ((inode
->i_sb
->s_flags
& SB_NODIRATIME
) && S_ISDIR(inode
->i_mode
))
1721 if (mnt
->mnt_flags
& MNT_NOATIME
)
1723 if ((mnt
->mnt_flags
& MNT_NODIRATIME
) && S_ISDIR(inode
->i_mode
))
1726 now
= current_time(inode
);
1728 if (!relatime_need_update(mnt
, inode
, now
))
1731 if (timespec64_equal(&inode
->i_atime
, &now
))
1737 void touch_atime(const struct path
*path
)
1739 struct vfsmount
*mnt
= path
->mnt
;
1740 struct inode
*inode
= d_inode(path
->dentry
);
1741 struct timespec64 now
;
1743 if (!atime_needs_update(path
, inode
))
1746 if (!sb_start_write_trylock(inode
->i_sb
))
1749 if (__mnt_want_write(mnt
) != 0)
1752 * File systems can error out when updating inodes if they need to
1753 * allocate new space to modify an inode (such is the case for
1754 * Btrfs), but since we touch atime while walking down the path we
1755 * really don't care if we failed to update the atime of the file,
1756 * so just ignore the return value.
1757 * We may also fail on filesystems that have the ability to make parts
1758 * of the fs read only, e.g. subvolumes in Btrfs.
1760 now
= current_time(inode
);
1761 update_time(inode
, &now
, S_ATIME
);
1762 __mnt_drop_write(mnt
);
1764 sb_end_write(inode
->i_sb
);
1766 EXPORT_SYMBOL(touch_atime
);
1769 * The logic we want is
1771 * if suid or (sgid and xgrp)
1774 int should_remove_suid(struct dentry
*dentry
)
1776 umode_t mode
= d_inode(dentry
)->i_mode
;
1779 /* suid always must be killed */
1780 if (unlikely(mode
& S_ISUID
))
1781 kill
= ATTR_KILL_SUID
;
1784 * sgid without any exec bits is just a mandatory locking mark; leave
1785 * it alone. If some exec bits are set, it's a real sgid; kill it.
1787 if (unlikely((mode
& S_ISGID
) && (mode
& S_IXGRP
)))
1788 kill
|= ATTR_KILL_SGID
;
1790 if (unlikely(kill
&& !capable(CAP_FSETID
) && S_ISREG(mode
)))
1795 EXPORT_SYMBOL(should_remove_suid
);
1798 * Return mask of changes for notify_change() that need to be done as a
1799 * response to write or truncate. Return 0 if nothing has to be changed.
1800 * Negative value on error (change should be denied).
1802 int dentry_needs_remove_privs(struct dentry
*dentry
)
1804 struct inode
*inode
= d_inode(dentry
);
1808 if (IS_NOSEC(inode
))
1811 mask
= should_remove_suid(dentry
);
1812 ret
= security_inode_need_killpriv(dentry
);
1816 mask
|= ATTR_KILL_PRIV
;
1820 static int __remove_privs(struct dentry
*dentry
, int kill
)
1822 struct iattr newattrs
;
1824 newattrs
.ia_valid
= ATTR_FORCE
| kill
;
1826 * Note we call this on write, so notify_change will not
1827 * encounter any conflicting delegations:
1829 return notify_change(dentry
, &newattrs
, NULL
);
1833 * Remove special file priviledges (suid, capabilities) when file is written
1836 int file_remove_privs(struct file
*file
)
1838 struct dentry
*dentry
= file_dentry(file
);
1839 struct inode
*inode
= file_inode(file
);
1844 * Fast path for nothing security related.
1845 * As well for non-regular files, e.g. blkdev inodes.
1846 * For example, blkdev_write_iter() might get here
1847 * trying to remove privs which it is not allowed to.
1849 if (IS_NOSEC(inode
) || !S_ISREG(inode
->i_mode
))
1852 kill
= dentry_needs_remove_privs(dentry
);
1856 error
= __remove_privs(dentry
, kill
);
1858 inode_has_no_xattr(inode
);
1862 EXPORT_SYMBOL(file_remove_privs
);
1865 * file_update_time - update mtime and ctime time
1866 * @file: file accessed
1868 * Update the mtime and ctime members of an inode and mark the inode
1869 * for writeback. Note that this function is meant exclusively for
1870 * usage in the file write path of filesystems, and filesystems may
1871 * choose to explicitly ignore update via this function with the
1872 * S_NOCMTIME inode flag, e.g. for network filesystem where these
1873 * timestamps are handled by the server. This can return an error for
1874 * file systems who need to allocate space in order to update an inode.
1877 int file_update_time(struct file
*file
)
1879 struct inode
*inode
= file_inode(file
);
1880 struct timespec64 now
;
1884 /* First try to exhaust all avenues to not sync */
1885 if (IS_NOCMTIME(inode
))
1888 now
= current_time(inode
);
1889 if (!timespec64_equal(&inode
->i_mtime
, &now
))
1892 if (!timespec64_equal(&inode
->i_ctime
, &now
))
1895 if (IS_I_VERSION(inode
) && inode_iversion_need_inc(inode
))
1896 sync_it
|= S_VERSION
;
1901 /* Finally allowed to write? Takes lock. */
1902 if (__mnt_want_write_file(file
))
1905 ret
= update_time(inode
, &now
, sync_it
);
1906 __mnt_drop_write_file(file
);
1910 EXPORT_SYMBOL(file_update_time
);
1912 /* Caller must hold the file's inode lock */
1913 int file_modified(struct file
*file
)
1918 * Clear the security bits if the process is not being run by root.
1919 * This keeps people from modifying setuid and setgid binaries.
1921 err
= file_remove_privs(file
);
1925 if (unlikely(file
->f_mode
& FMODE_NOCMTIME
))
1928 return file_update_time(file
);
1930 EXPORT_SYMBOL(file_modified
);
1932 int inode_needs_sync(struct inode
*inode
)
1936 if (S_ISDIR(inode
->i_mode
) && IS_DIRSYNC(inode
))
1940 EXPORT_SYMBOL(inode_needs_sync
);
1943 * If we try to find an inode in the inode hash while it is being
1944 * deleted, we have to wait until the filesystem completes its
1945 * deletion before reporting that it isn't found. This function waits
1946 * until the deletion _might_ have completed. Callers are responsible
1947 * to recheck inode state.
1949 * It doesn't matter if I_NEW is not set initially, a call to
1950 * wake_up_bit(&inode->i_state, __I_NEW) after removing from the hash list
1953 static void __wait_on_freeing_inode(struct inode
*inode
)
1955 wait_queue_head_t
*wq
;
1956 DEFINE_WAIT_BIT(wait
, &inode
->i_state
, __I_NEW
);
1957 wq
= bit_waitqueue(&inode
->i_state
, __I_NEW
);
1958 prepare_to_wait(wq
, &wait
.wq_entry
, TASK_UNINTERRUPTIBLE
);
1959 spin_unlock(&inode
->i_lock
);
1960 spin_unlock(&inode_hash_lock
);
1962 finish_wait(wq
, &wait
.wq_entry
);
1963 spin_lock(&inode_hash_lock
);
1966 static __initdata
unsigned long ihash_entries
;
1967 static int __init
set_ihash_entries(char *str
)
1971 ihash_entries
= simple_strtoul(str
, &str
, 0);
1974 __setup("ihash_entries=", set_ihash_entries
);
1977 * Initialize the waitqueues and inode hash table.
1979 void __init
inode_init_early(void)
1981 /* If hashes are distributed across NUMA nodes, defer
1982 * hash allocation until vmalloc space is available.
1988 alloc_large_system_hash("Inode-cache",
1989 sizeof(struct hlist_head
),
1992 HASH_EARLY
| HASH_ZERO
,
1999 void __init
inode_init(void)
2001 /* inode slab cache */
2002 inode_cachep
= kmem_cache_create("inode_cache",
2003 sizeof(struct inode
),
2005 (SLAB_RECLAIM_ACCOUNT
|SLAB_PANIC
|
2006 SLAB_MEM_SPREAD
|SLAB_ACCOUNT
),
2009 /* Hash may have been set up in inode_init_early */
2014 alloc_large_system_hash("Inode-cache",
2015 sizeof(struct hlist_head
),
2025 void init_special_inode(struct inode
*inode
, umode_t mode
, dev_t rdev
)
2027 inode
->i_mode
= mode
;
2028 if (S_ISCHR(mode
)) {
2029 inode
->i_fop
= &def_chr_fops
;
2030 inode
->i_rdev
= rdev
;
2031 } else if (S_ISBLK(mode
)) {
2032 inode
->i_fop
= &def_blk_fops
;
2033 inode
->i_rdev
= rdev
;
2034 } else if (S_ISFIFO(mode
))
2035 inode
->i_fop
= &pipefifo_fops
;
2036 else if (S_ISSOCK(mode
))
2037 ; /* leave it no_open_fops */
2039 printk(KERN_DEBUG
"init_special_inode: bogus i_mode (%o) for"
2040 " inode %s:%lu\n", mode
, inode
->i_sb
->s_id
,
2043 EXPORT_SYMBOL(init_special_inode
);
2046 * inode_init_owner - Init uid,gid,mode for new inode according to posix standards
2048 * @dir: Directory inode
2049 * @mode: mode of the new inode
2051 void inode_init_owner(struct inode
*inode
, const struct inode
*dir
,
2054 inode
->i_uid
= current_fsuid();
2055 if (dir
&& dir
->i_mode
& S_ISGID
) {
2056 inode
->i_gid
= dir
->i_gid
;
2058 /* Directories are special, and always inherit S_ISGID */
2061 else if ((mode
& (S_ISGID
| S_IXGRP
)) == (S_ISGID
| S_IXGRP
) &&
2062 !in_group_p(inode
->i_gid
) &&
2063 !capable_wrt_inode_uidgid(dir
, CAP_FSETID
))
2066 inode
->i_gid
= current_fsgid();
2067 inode
->i_mode
= mode
;
2069 EXPORT_SYMBOL(inode_init_owner
);
2072 * inode_owner_or_capable - check current task permissions to inode
2073 * @inode: inode being checked
2075 * Return true if current either has CAP_FOWNER in a namespace with the
2076 * inode owner uid mapped, or owns the file.
2078 bool inode_owner_or_capable(const struct inode
*inode
)
2080 struct user_namespace
*ns
;
2082 if (uid_eq(current_fsuid(), inode
->i_uid
))
2085 ns
= current_user_ns();
2086 if (kuid_has_mapping(ns
, inode
->i_uid
) && ns_capable(ns
, CAP_FOWNER
))
2090 EXPORT_SYMBOL(inode_owner_or_capable
);
2093 * Direct i/o helper functions
2095 static void __inode_dio_wait(struct inode
*inode
)
2097 wait_queue_head_t
*wq
= bit_waitqueue(&inode
->i_state
, __I_DIO_WAKEUP
);
2098 DEFINE_WAIT_BIT(q
, &inode
->i_state
, __I_DIO_WAKEUP
);
2101 prepare_to_wait(wq
, &q
.wq_entry
, TASK_UNINTERRUPTIBLE
);
2102 if (atomic_read(&inode
->i_dio_count
))
2104 } while (atomic_read(&inode
->i_dio_count
));
2105 finish_wait(wq
, &q
.wq_entry
);
2109 * inode_dio_wait - wait for outstanding DIO requests to finish
2110 * @inode: inode to wait for
2112 * Waits for all pending direct I/O requests to finish so that we can
2113 * proceed with a truncate or equivalent operation.
2115 * Must be called under a lock that serializes taking new references
2116 * to i_dio_count, usually by inode->i_mutex.
2118 void inode_dio_wait(struct inode
*inode
)
2120 if (atomic_read(&inode
->i_dio_count
))
2121 __inode_dio_wait(inode
);
2123 EXPORT_SYMBOL(inode_dio_wait
);
2126 * inode_set_flags - atomically set some inode flags
2128 * Note: the caller should be holding i_mutex, or else be sure that
2129 * they have exclusive access to the inode structure (i.e., while the
2130 * inode is being instantiated). The reason for the cmpxchg() loop
2131 * --- which wouldn't be necessary if all code paths which modify
2132 * i_flags actually followed this rule, is that there is at least one
2133 * code path which doesn't today so we use cmpxchg() out of an abundance
2136 * In the long run, i_mutex is overkill, and we should probably look
2137 * at using the i_lock spinlock to protect i_flags, and then make sure
2138 * it is so documented in include/linux/fs.h and that all code follows
2139 * the locking convention!!
2141 void inode_set_flags(struct inode
*inode
, unsigned int flags
,
2144 WARN_ON_ONCE(flags
& ~mask
);
2145 set_mask_bits(&inode
->i_flags
, mask
, flags
);
2147 EXPORT_SYMBOL(inode_set_flags
);
2149 void inode_nohighmem(struct inode
*inode
)
2151 mapping_set_gfp_mask(inode
->i_mapping
, GFP_USER
);
2153 EXPORT_SYMBOL(inode_nohighmem
);
2156 * timespec64_trunc - Truncate timespec64 to a granularity
2158 * @gran: Granularity in ns.
2160 * Truncate a timespec64 to a granularity. Always rounds down. gran must
2161 * not be 0 nor greater than a second (NSEC_PER_SEC, or 10^9 ns).
2163 struct timespec64
timespec64_trunc(struct timespec64 t
, unsigned gran
)
2165 /* Avoid division in the common cases 1 ns and 1 s. */
2168 } else if (gran
== NSEC_PER_SEC
) {
2170 } else if (gran
> 1 && gran
< NSEC_PER_SEC
) {
2171 t
.tv_nsec
-= t
.tv_nsec
% gran
;
2173 WARN(1, "illegal file time granularity: %u", gran
);
2177 EXPORT_SYMBOL(timespec64_trunc
);
2180 * timestamp_truncate - Truncate timespec to a granularity
2182 * @inode: inode being updated
2184 * Truncate a timespec to the granularity supported by the fs
2185 * containing the inode. Always rounds down. gran must
2186 * not be 0 nor greater than a second (NSEC_PER_SEC, or 10^9 ns).
2188 struct timespec64
timestamp_truncate(struct timespec64 t
, struct inode
*inode
)
2190 struct super_block
*sb
= inode
->i_sb
;
2191 unsigned int gran
= sb
->s_time_gran
;
2193 t
.tv_sec
= clamp(t
.tv_sec
, sb
->s_time_min
, sb
->s_time_max
);
2194 if (unlikely(t
.tv_sec
== sb
->s_time_max
|| t
.tv_sec
== sb
->s_time_min
))
2197 /* Avoid division in the common cases 1 ns and 1 s. */
2200 else if (gran
== NSEC_PER_SEC
)
2202 else if (gran
> 1 && gran
< NSEC_PER_SEC
)
2203 t
.tv_nsec
-= t
.tv_nsec
% gran
;
2205 WARN(1, "invalid file time granularity: %u", gran
);
2208 EXPORT_SYMBOL(timestamp_truncate
);
2211 * current_time - Return FS time
2214 * Return the current time truncated to the time granularity supported by
2217 * Note that inode and inode->sb cannot be NULL.
2218 * Otherwise, the function warns and returns time without truncation.
2220 struct timespec64
current_time(struct inode
*inode
)
2222 struct timespec64 now
;
2224 ktime_get_coarse_real_ts64(&now
);
2226 if (unlikely(!inode
->i_sb
)) {
2227 WARN(1, "current_time() called with uninitialized super_block in the inode");
2231 return timestamp_truncate(now
, inode
);
2233 EXPORT_SYMBOL(current_time
);
2236 * Generic function to check FS_IOC_SETFLAGS values and reject any invalid
2239 * Note: the caller should be holding i_mutex, or else be sure that they have
2240 * exclusive access to the inode structure.
2242 int vfs_ioc_setflags_prepare(struct inode
*inode
, unsigned int oldflags
,
2246 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
2247 * the relevant capability.
2249 * This test looks nicer. Thanks to Pauline Middelink
2251 if ((flags
^ oldflags
) & (FS_APPEND_FL
| FS_IMMUTABLE_FL
) &&
2252 !capable(CAP_LINUX_IMMUTABLE
))
2257 EXPORT_SYMBOL(vfs_ioc_setflags_prepare
);
2260 * Generic function to check FS_IOC_FSSETXATTR values and reject any invalid
2263 * Note: the caller should be holding i_mutex, or else be sure that they have
2264 * exclusive access to the inode structure.
2266 int vfs_ioc_fssetxattr_check(struct inode
*inode
, const struct fsxattr
*old_fa
,
2270 * Can't modify an immutable/append-only file unless we have
2271 * appropriate permission.
2273 if ((old_fa
->fsx_xflags
^ fa
->fsx_xflags
) &
2274 (FS_XFLAG_IMMUTABLE
| FS_XFLAG_APPEND
) &&
2275 !capable(CAP_LINUX_IMMUTABLE
))
2279 * Project Quota ID state is only allowed to change from within the init
2280 * namespace. Enforce that restriction only if we are trying to change
2281 * the quota ID state. Everything else is allowed in user namespaces.
2283 if (current_user_ns() != &init_user_ns
) {
2284 if (old_fa
->fsx_projid
!= fa
->fsx_projid
)
2286 if ((old_fa
->fsx_xflags
^ fa
->fsx_xflags
) &
2287 FS_XFLAG_PROJINHERIT
)
2291 /* Check extent size hints. */
2292 if ((fa
->fsx_xflags
& FS_XFLAG_EXTSIZE
) && !S_ISREG(inode
->i_mode
))
2295 if ((fa
->fsx_xflags
& FS_XFLAG_EXTSZINHERIT
) &&
2296 !S_ISDIR(inode
->i_mode
))
2299 if ((fa
->fsx_xflags
& FS_XFLAG_COWEXTSIZE
) &&
2300 !S_ISREG(inode
->i_mode
) && !S_ISDIR(inode
->i_mode
))
2304 * It is only valid to set the DAX flag on regular files and
2305 * directories on filesystems.
2307 if ((fa
->fsx_xflags
& FS_XFLAG_DAX
) &&
2308 !(S_ISREG(inode
->i_mode
) || S_ISDIR(inode
->i_mode
)))
2311 /* Extent size hints of zero turn off the flags. */
2312 if (fa
->fsx_extsize
== 0)
2313 fa
->fsx_xflags
&= ~(FS_XFLAG_EXTSIZE
| FS_XFLAG_EXTSZINHERIT
);
2314 if (fa
->fsx_cowextsize
== 0)
2315 fa
->fsx_xflags
&= ~FS_XFLAG_COWEXTSIZE
;
2319 EXPORT_SYMBOL(vfs_ioc_fssetxattr_check
);